Odell Barnes joins a growing list of death row inmates whose convictions have become a lot less clear-cut during the appeals process.

Odell Barnes joins a growing list of death row inmates whose convictions have become a lot less clear-cut during the appeals process. That's supposed to be the point of an appeal: a chance to revisit the case and make sure that if a serious mistake was made at the trial, that mistake can be corrected.

But short of exoneration by DNA evidence or identification of another perpetrator, the condemned have a tough time getting relief. "You pretty much have to establish a very convincing case against somebody else," says Dick Burr, who has handled dozens of death penalty appeals in his career. "Then, maybe the government intervenes. Maybe not."

While most abhor the notion that innocent people would be executed, Burr says, there's a tendency to want to believe that anyone on death row probably deserves it. "I think there's kind of a rationalization process that goes on," Burr says. "The guy really did it, or killed somebody else, or they're bad people."

Robber and rapist Gary Graham may not be a killer.

The fact is, most of the people on death row did do something bad at one point, or even commited multiple crimes. And offenders usually repeat, which makes them logical suspects in a murder investigation. Barnes, for example, admits to one of his rape convictions and several robberies.

But as several high-profile cases in the past few years have shown, assumptions of guilt sometimes turn out to be erroneous -- even after a jury has returned a death sentence. In 1999 alone, eight inmates were cleared of their charges. In Illinois, where ten death row inmates have been exonerated in recent years, Anthony Porter was released after 16 years -- two days before his scheduled execution.

Since the U.S. death penalty was reinstated in 1976, 84 people have escaped the executioner, more than 1 percent of the 6,500 people sentenced to die.

In Texas, which has executed more inmates than any other state, only a few have escaped the death sentence. The most recent was Henry Lee Lucas, whose sentence was commuted in 1998. Though he confessed to 600 murders, Lucas got the death penalty for only one; time sheets and a cashed check later found by reporters showed he was in Florida when the murder occurred.

After nine years, Federico Macias was vindicated in 1993, when a former cell mate testified in federal court that he had committed perjury. And millions have seen the documentary The Thin Blue Line about Randall Dale Adams. He was convicted largely on the testimony of star witness David Harris, who later confessed to the killing.

But like Barnes, others in Texas have raised disturbing issues about their convictions. As with Barnes, their criminal records led authorities to their doorstep. Like Barnes, their attorneys at trial did a poor job defending them. And like Barnes, the new information has yet to stop the clock as it ticks toward their appointed hour with the executioner. The list:

Gary Graham

Robber and rapist Gary Graham was convicted of killing Bobby Grant Lambert outside a Houston store in 1981. According to witnesses, an assailant confronted Lambert in the parking lot, a struggle ensued, and Lambert was killed.

Graham was arrested a week later, after robbing and raping a 57-year-old woman -- then passing out drunk in her bed. He was later connected to a string of armed robberies that occurred during the same week.

A composite sketch was drawn that several witnesses said closely resembled the killer. Only one witness, Bernadine Skillern, picked Graham out of a lineup. At trial, Skillern's testimony was the state's primary evidence. In the penalty phase, the prosecutor noted that Graham had been arrested with a .22-caliber handgun; Lambert had been killed by a .22.

No other witnesses were asked to testify. Since then, two others have been found. For various reasons, none of them except Skillern asserted that Graham was the assailant. The others agreed that the killer was shorter than Lambert, who stood five foot six, three inches shorter than Graham. The composite drawing looks very different from Graham.

And ballistic tests revealed that the .22 that killed Lambert was not the same gun in Graham's possession when he was arrested, a fact that police knew during the trial but did not disclose.

Graham's attorney, Dick Burr, says he has not had much success getting his new evidence introduced for review. "We've never been able to get a hearing on any of this stuff," Burr says. After two postponements, no new execution date has been set.

Michael Blair

On September 4, 1993, seven-year-old Ashley Estell was murdered after wandering away from a Plano soccer field. Convicted child molester Michael Blair was arrested ten days later and charged in Estell's killing.

At trial, the state presented evidence that Blair had signed up as a volunteer in the search party after Estell disappeared and that he was twice seen driving near the spot after the killing. Two hair samples consistent with the victim's were found in his car; samples of fiber from a stuffed animal found in his car were consistent with fibers found on the victim, and hairs similar to the victim's and Blair's were found "clumped together" in a nearby park. Three witnesses saw him at the soccer field the morning of her disappearance.

Blair was convicted and sentenced to death, even though three other witnesses unrelated to him vouched for his alibi.

New evidence convincingly contradicts the state's evidence. One of the three witnesses who had seen Blair at the scene said Blair drove away at least an hour before the abduction. Another identified the man he saw as Hispanic and taller than himself (Blair is white and shorter). The third said he noticed the suspect standing alone on the field -- after the girl had been reported missing.

DNA analysis revealed that the hair in Blair's car was not the victim's, and scientific analyses of the other hairs and fibers either disproved the connection or were inconclusive. A Plano police detective testified that his supervisor had told him to destroy a police report because it might help Blair's attorneys. And a more likely suspect, when asked questions about the case during a deposition, took the Fifth Amendment and refused to answer.

Roger McGowen

In March 1986 a gunman in a ski mask entered Just Marion and Lynn's nightclub in Houston a short time after midnight. He waved the bartender toward the cash register, then fled after apparently exchanging gunfire with bar owner Marion Elizabeth Pantzer, who died from a gunshot wound.

Several weeks later police arrested Roger McGowen, a small-time thug with a penchant for armed robbery. His fate at trial was sealed with a signed confession, which McGowen says was coerced by police.

McGowen's three sisters tried to contact his defense attorney, but he never called them back. They later testified that McGowen had been with them at a family function on the night of the murder.

Another witness testified that McGowen's brother had come to his door, saying he'd been shot while trying to rob "a place." Other witnesses added statements that implicated the brother and a cousin, who had been in the bar earlier in the evening.

Innocent or not, Barnes, Graham, Blair and McGowen still have at least a theoretical chance for a reprieve. The same cannot be said of David Spence, who was executed in 1997 for brutally killing three Waco teenagers. Spence, who became the subject of a Dateline NBC program, was indicted 17 months after the murders while serving time for aggravated sexual assault. A number of inmates testified at trial that he'd bragged of the crime.

Later, all seven witnesses to his alleged confession recanted, signing affidavits that they had been offered favors in exchange for their testimony. Two other men, who in exchange for leniency had stated they were with Spence when the murders occurred, later said they had made it all up to save their necks. It took police five tries before they came up with a written confession they could run with, changing vehicles and other details to fit their scenario. And a possible suspect who had bragged to witnesses -- not inmates -- about the murders later told police he'd been watching Dynasty on television that night. The murder happened on a Tuesday. Dynasty aired on Wednesdays.